Code Index:

package MHonArc::CharEnt
- str2sgml
- _utf8_to_sgml
__END__
EOF

NAME

MHonArc::CharEnt - HTML Character routines for MHonArc.

SYNOPSIS

  use MHonArc::CharEnt;

  MHonArc resource file:

    <CharsetConverters>
    ...
    iso-8859-15;    MHonArc::CharEnt::str2sgml;     MHonArc/CharEnt.pm
    ...
    </CharsetConverters>

DESCRIPTION

MHonArc::CharEnt provides the main character conversion routine used by MHonArc for converting non-ASCII encoded message header data and text/plain character data into HTML. This module was initially written to just support 8-bit only charsets. However, it has been extended to support multibyte charsets.

All characters are mapped to HTML 4.0 character entity references (e.g. < >) or to Unicode numeric character entity references (e.g. ‾). Most modern browsers will support the Unicode references directly.

NOTES

This module relies on MHonArc's CHARSETALIASES resource for defining alternate names for charset supported.
Most character conversion is done through mapping tables that are dynamicly loaded on a as-needed basis. There is probably room for optimization by trying to replace tables for charsets with algorithmic conversion solutions.

UTF-8 conversion is done algorithmically.
A main goal of this module is to convert raw non-ASCII data of various character sets to ASCII data using entity references for non-ASCII characters. This way, archive files will all be in ASCII, with modern compliant HTML browsers being able to handle the rendering of non-ASCII characters from the standard named and numeric character entity references.

This does make reading the raw HTML source for non-English languages difficult, but this may be a non-issue with most users.

VERSION

$Id: CharEnt.pm,v 1.17 2010/12/31 18:23:02 ehood Exp $

AUTHOR

Earl Hood, earl@earlhood.com

MHonArc comes with ABSOLUTELY NO WARRANTY and MHonArc may be copied only under the terms of the GNU General Public License, which may be found in the MHonArc distribution.

##---------------------------------------------------------------------------## ## File: ## $Id: CharEnt.pm,v 1.17 2010/12/31 18:23:02 ehood Exp $ ## Author: ## Earl Hood earl@earlhood.com ## Description: ## POD after __END__ ##---------------------------------------------------------------------------## ## Copyright (C) 1997-2002 Earl Hood, earl@earlhood.com ## ## This program is free software; you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by ## the Free Software Foundation; either version 2 of the License, or ## (at your option) any later version. ## ## This program is distributed in the hope that it will be useful, ## but WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with this program; if not, write to the Free Software ## Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA ## 02111-1307, USA ##---------------------------------------------------------------------------## package MHonArc::CharEnt; use strict; use MHonArc::CharMaps; use MHonArc::Char; ##--------------------------------------------------------------------------- ## Charset specification to mapping ##--------------------------------------------------------------------------- ## NOTE: The mapping uses a single name for a charset. ## The CHARSETALIASES resource can be used to map aka names (aliases) ## to the names used here. ## NOTE: UTF-8 does not require a map since UTF-8 is decoded straight ## to &#xHHHH; entity references. ## NOTE: iso-2022-{jp,kr} are translated to euc-{jp,kr} first before ## conversion. my %CharsetMaps = ( 'iso-8859-1' => 'MHonArc/CharEnt/ISO8859_1.pm', 'iso-8859-2' => 'MHonArc/CharEnt/ISO8859_2.pm', 'iso-8859-3' => 'MHonArc/CharEnt/ISO8859_3.pm', 'iso-8859-4' => 'MHonArc/CharEnt/ISO8859_4.pm', 'iso-8859-5' => 'MHonArc/CharEnt/ISO8859_5.pm', 'iso-8859-6' => 'MHonArc/CharEnt/ISO8859_6.pm', 'iso-8859-7' => 'MHonArc/CharEnt/ISO8859_7.pm', 'iso-8859-8' => 'MHonArc/CharEnt/ISO8859_8.pm', 'iso-8859-9' => 'MHonArc/CharEnt/ISO8859_9.pm', 'iso-8859-10' => 'MHonArc/CharEnt/ISO8859_10.pm', 'iso-8859-11' => 'MHonArc/CharEnt/ISO8859_11.pm', 'iso-8859-13' => 'MHonArc/CharEnt/ISO8859_13.pm', 'iso-8859-14' => 'MHonArc/CharEnt/ISO8859_14.pm', 'iso-8859-15' => 'MHonArc/CharEnt/ISO8859_15.pm', 'iso-8859-16' => 'MHonArc/CharEnt/ISO8859_16.pm', 'cp866' => 'MHonArc/CharEnt/CP866.pm', 'cp949' => 'MHonArc/CharEnt/CP949.pm', # euc-kr 'cp932' => 'MHonArc/CharEnt/CP932.pm', # shiftjis 'cp936' => 'MHonArc/CharEnt/CP936.pm', # GBK 'cp950' => 'MHonArc/CharEnt/CP950.pm', 'cp1250' => 'MHonArc/CharEnt/CP1250.pm', 'cp1251' => 'MHonArc/CharEnt/CP1251.pm', 'cp1252' => 'MHonArc/CharEnt/CP1252.pm', 'cp1253' => 'MHonArc/CharEnt/CP1253.pm', 'cp1254' => 'MHonArc/CharEnt/CP1254.pm', 'cp1255' => 'MHonArc/CharEnt/CP1255.pm', 'cp1256' => 'MHonArc/CharEnt/CP1256.pm', 'cp1257' => 'MHonArc/CharEnt/CP1257.pm', 'cp1258' => 'MHonArc/CharEnt/CP1258.pm', 'koi-0' => 'MHonArc/CharEnt/KOI_0.pm', 'koi-7' => 'MHonArc/CharEnt/KOI_7.pm', 'koi8-a' => 'MHonArc/CharEnt/KOI8_A.pm', 'koi8-b' => 'MHonArc/CharEnt/KOI8_B.pm', 'koi8-e' => 'MHonArc/CharEnt/KOI8_E.pm', 'koi8-f' => 'MHonArc/CharEnt/KOI8_F.pm', 'koi8-r' => 'MHonArc/CharEnt/KOI8_R.pm', 'koi8-u' => 'MHonArc/CharEnt/KOI8_U.pm', 'gost19768-87' => 'MHonArc/CharEnt/GOST19768_87.pm', 'viscii' => 'MHonArc/CharEnt/VISCII.pm', 'macarabic' => 'MHonArc/CharEnt/AppleArabic.pm', 'maccentraleurroman' => 'MHonArc/CharEnt/AppleCenteuro.pm', 'maccroatian' => 'MHonArc/CharEnt/AppleCroatian.pm', 'maccyrillic' => 'MHonArc/CharEnt/AppleCyrillic.pm', 'macgreek' => 'MHonArc/CharEnt/AppleGreek.pm', 'machebrew' => 'MHonArc/CharEnt/AppleHebrew.pm', 'macicelandic' => 'MHonArc/CharEnt/AppleIceland.pm', 'macromanian' => 'MHonArc/CharEnt/AppleRomanian.pm', 'macroman' => 'MHonArc/CharEnt/AppleRoman.pm', 'macthai' => 'MHonArc/CharEnt/AppleThai.pm', 'macturkish' => 'MHonArc/CharEnt/AppleTurkish.pm', 'big5-eten' => 'MHonArc/CharEnt/BIG5_ETEN.pm', 'big5-hkscs' => 'MHonArc/CharEnt/BIG5_HKSCS.pm', 'gb2312' => 'MHonArc/CharEnt/GB2312.pm', 'euc-jp' => 'MHonArc/CharEnt/EUC_JP.pm', 'hp-roman8' => 'MHonArc/CharEnt/HP_ROMAN8.pm', ); my $char_maps = MHonArc::CharMaps->new(\%CharsetMaps); ############################################################################### ## Routines ############################################################################### sub str2sgml { my $data = shift; my $charset = lc shift; my $data_r = ref($data) ? $data : \$data; $charset =~ tr/_/-/; # UTF-8 can be converted algorithmically. if ($charset eq 'utf-8') { _utf8_to_sgml($data_r); return $$data_r; } # If us-ascii, use simple s/// operation. if ($charset eq 'us-ascii') { $$data_r =~ s/([$HTMLSpecials])/$HTMLSpecials{$1}/go; return $$data_r; } MHonArc::Char::map_conv($data_r, $charset, $char_maps, \%HTMLSpecials); } ##---------------------------------------------------------------------------## ## Private Routines. # Array of masks for lead byte in UTF-8 (for Perl <5.6) # This could be computed on-the-fly, but using an array is faster my @utf8_lb_mask = ( 0x3F, 0x1F, 0xF, 0x7, 0x3, 0x1 # 1, 2, 3, 4, 5, 6 bytes, respectively ); # Regex pattern for UTF-8 data my $utf8_re = q/([\x00-\x7F]| [\xC0-\xDF][\x80-\xBF]| \xE0 [\xA0-\xBF][\x80-\xBF]| [\xE1-\xEF][\x80-\xBF]{2}| \xF0 [\x90-\xBF][\x80-\xBF]{2}| [\xF1-\xF7][\x80-\xBF]{3}| \xF8 [\x88-\xBF][\x80-\xBF]{3}| [\xF9-\xFB][\x80-\xBF]{4}| \xFC [\x84-\xBF][\x80-\xBF]{4}| \xFD [\x80-\xBF]{5}| .)/; # A lax regex for UTF-8 data. Used for utf-8-aware perl since perl # will validate sequences my $utf8_re_lax = q/([\x00-\x7F]| [\xC0-\xDF][\x00-\xFF]| [\xE0-\xEF][\x00-\xFF]{2}| [\xF0-\xF7][\x00-\xFF]{3}| [\xF8-\xFB][\x00-\xFF]{4}| [\xFC-\xFD][\x00-\xFF]{5}| .)/; sub _utf8_to_sgml { my $data_r = shift; if ($] >= 5.006) { # UTF-8-aware perl # Have to enable warnings to get stricter utf-8 checks for Perl 5.8 use warnings; my($char, $ord, $malformed); # Define local warn handle to suppress malformed utf-8 warning # messages and to flag when such occurrences happen. my $cur_sig_warn = $SIG{__WARN__}; local $SIG{__WARN__} = sub { $malformed = 1; #warn @_; # invoke current warn handler, if defined &$cur_sig_warn if defined($cur_sig_warn) && ref($cur_sig_warn); }; $$data_r =~ s{ $utf8_re_lax }{ # Bug #26577: Perl 5.10 changed unpack behavior $char = ($] >= 5.010)? unpack('C0U*',$1): unpack('U0U*',$1); if ($malformed || (($char & 0xFFFE) == 0xFFFE) || (($char & 0xFFFF) == 0xFFFF) || ($char >= 0xFDD0 && $char <= 0xFDEF) || ($char >= 0xD800 && $char <= 0xDFFF) ) { # Some of the if() checks may be handled by perl directly, # but such checks can be disabled when perl is built. $malformed = 0; '�'; } else { ($char <= 0x7F) ? $HTMLSpecials{$1} || sprintf('%c',$char) : sprintf('&#x%X;',$char); } }gxeso; } else { # non-UTF-8-aware perl my($i, $n, $char); $$data_r =~ s{ $utf8_re }{ if (($n = length($1)) == 1) { my $ord = ord($1); if ($ord > 0x7F) { # Malformed sequence '�'; } else { # 7-bit ASCII $HTMLSpecials{$1} || $1; } } else { # Multi-byte sequence $char = (unpack('C',substr($1,0,1)) & $utf8_lb_mask[$n-1]) << ($n-1)*6; for ($i=1; $i < $n; ++$i) { $char |= ((unpack('C',substr($1,$i,1)) & 0x3F) << (($n-$i-1)*6)); } if ($char <= 0x7F || # should only be single byte sequence (($char & 0xFFFE) == 0xFFFE) || # not a char (($char & 0xFFFF) == 0xFFFF) || # not a char ($char >= 0xFDD0 && $char <= 0xFDEF) || # not a char ($char >= 0xD800 && $char <= 0xDFFF) # surrogates ) { '�'; } else { sprintf('&#x%X;',$char); } } }gxseo; } } ##---------------------------------------------------------------------------## 1; __END__